Plant roots are critical organs of vascular plant species. It is well known that roots provide water uptake while physical support to the plant. Roots also extract mineral and organic nutrients from the soil or growth medium, and produce a number of important natural products, such as hormones and defense compounds that impact plant growth and development. Roots may act as a storage organ for nutrients or contain chemicals that are pharmaceutically important. Establishment of an appropriate root structure is important for the plant to maximize its growth potential and production.
Due to the complexity of the development of plant roots, it has been difficult to identify mechanisms to enhance root growth while maintaining the health of the entire plant. The processes that lead to increased root growth involve multiple mechanisms of cellular adaptation and numerous metabolic pathways. In addition, a pathway that increases root growth may negatively impact shoot, stem or leaf growth.
During their life cycle, plants may be at risk for exposure to environmentally stressful conditions. These conditions can include limited access to water (such as drought), or exposure to high or low temperatures. If the duration or severity of these stressful conditions is too great, the exposed plants may have reduced growth and yield. While plants have mechanisms to mitigate the effects of environmentally stressful conditions, continuous exposure may cause damage to the plants and can result in death of the plant. Reduced crop yield or death of crop plants due to environmentally stressful conditions is a major concern of crop plant growers.
Strong root growth allows for the plants to be more competitive with surrounding plants, such as weeds, for water and nutrient resources. This is especially true in areas where the plant might be exposed to environmentally stressful conditions. An enhanced root structure would allow the plants to increase their access to water and nutrients. Longer roots would allow the roots to reach new areas of the soil or growth medium. A larger root system provides a greater surface area for absorption of water and nutrients.
Therefore, there is a need in the art for compounds and methods to enhance root growth. There is a need for enhanced root growth that provides healthier and higher yielding plants. There is a need for enhanced root growth that provides protection to the plants from environmentally stressful conditions, such as drought or intense temperatures.